import XCTest
@testable import LChatCore

// 🤖 Parity tests for the native parseReminder port — the SAME cases the web
// suite pins (test/apps.test.mjs "remind: parseReminder …"), so the two parsers
// accept and reject identically. `now` is injected, so everything relative is
// exact; clock/date shapes assert on local-time components, like the web tests.
final class ReminderParseTests: XCTestCase {
    func testRelativeTimes() {
        XCTAssertEqual(ReminderParse.parse("Call mom in 2h", now: 0),
                       .init(text: "Call mom", when: 2 * 3_600_000))
        XCTAssertEqual(ReminderParse.parse("stretch in 45m", now: 1000),
                       .init(text: "stretch", when: 1000 + 45 * 60000))
    }

    func testClockTimeIsNextOccurrenceWithinADay() throws {
        let now = Date().timeIntervalSince1970 * 1000
        let at = try XCTUnwrap(ReminderParse.parse("Standup at 9:00", now: now))
        XCTAssertEqual(at.text, "Standup")
        XCTAssertGreaterThan(at.when, now)
        XCTAssertLessThanOrEqual(at.when, now + 24 * 3_600_000)
        let comps = Calendar.current.dateComponents([.hour, .minute],
                                                    from: Date(timeIntervalSince1970: at.when / 1000))
        XCTAssertEqual(comps.hour, 9)
        XCTAssertEqual(comps.minute, 0)
    }

    func testExplicitDateAfterBar() throws {
        let abs = try XCTUnwrap(ReminderParse.parse("Renew passport | 2026-08-01", now: 0))
        XCTAssertEqual(abs.text, "Renew passport")
        let d = Calendar.current.dateComponents([.year, .month, .day, .hour],
                                                from: Date(timeIntervalSince1970: abs.when / 1000))
        XCTAssertEqual(d.year, 2026)
        XCTAssertEqual(d.month, 8)
        XCTAssertEqual(d.day, 1)
        XCTAssertEqual(d.hour, 9, "a bare date defaults to 09:00")
    }

    func testSlackPhrasing() {
        // "me in 10 seconds to do a thing" — leading "me" dropped, time leads.
        XCTAssertEqual(ReminderParse.parse("me in 10 seconds to do a thing", now: 0),
                       .init(text: "do a thing", when: 10000))
        XCTAssertEqual(ReminderParse.parse("in 5 minutes to stretch", now: 1000),
                       .init(text: "stretch", when: 1000 + 5 * 60000))
        XCTAssertEqual(ReminderParse.parse("me to water plants in 1 h", now: 0),
                       .init(text: "water plants", when: 3_600_000))
        // "meeting" must NOT be read as the "me" keyword.
        XCTAssertEqual(ReminderParse.parse("meeting in 10m", now: 0),
                       .init(text: "meeting", when: 10 * 60000))
    }

    // Port-hardening edges from review: each of these crashed or silently
    // diverged from the web before being pinned here.
    func testNonASCIIDigitsAreRejectedNotCrashed() {
        // ICU \d matches Unicode digits ("٥") that Swift's numeric inits then
        // reject — the patterns must be [0-9] and the outcome a calm nil.
        XCTAssertNil(ReminderParse.parse("pray in ٥ minutes", now: 0))
        XCTAssertNil(ReminderParse.parse("bad | ٢٠٢٦-08-01", now: 0))
        XCTAssertNil(ReminderParse.parse("standup at ٩:00", now: 0))
    }

    func testSubCenturyYearsAreRejected() {
        // JS's new Date(26,…) means 1926 and fails its round-trip; 0026 must
        // not become 26 AD natively (it would file a permanently-due reminder).
        XCTAssertNil(ReminderParse.parse("renew passport | 0026-08-01", now: 0))
        XCTAssertNil(ReminderParse.parse("renew passport | 0099-01-01", now: 0))
    }

    func testNewlinesTrimLikeTheWeb() {
        // JS .trim() strips newlines; multi-line drafts must split identically.
        XCTAssertEqual(ReminderParse.parse("call mum \n| 2026-08-01", now: 0)?.text, "call mum")
        XCTAssertEqual(ReminderParse.parse("me \n in 10 s \n to stretch", now: 0)?.text, "stretch")
    }

    func testAbsurdRelativeAmountsDoNotProduceInfinity() {
        // A digit string big enough to overflow Double must reject (the web's
        // equivalent add is dropped in the fold), never propagate ±inf into
        // scheduling arithmetic.
        let huge = String(repeating: "9", count: 400)
        XCTAssertNil(ReminderParse.parse("call mum in \(huge) weeks", now: 0))
        // A large-but-finite amount still parses — the SERVER is the range
        // authority (postSchedule's horizon check), same as the web.
        XCTAssertNotNil(ReminderParse.parse("call mum in 999999999 weeks", now: 0))
    }

    func testRejections() {
        XCTAssertNil(ReminderParse.parse("just a note", now: 0))
        XCTAssertNil(ReminderParse.parse("", now: 0))
        XCTAssertNil(ReminderParse.parse("do it in 3x", now: 0), "unknown unit")
        XCTAssertNil(ReminderParse.parse("in 2h", now: 0), "no text before the time")
        // Explicit dates/times are rejected, never rolled over, when out of range.
        XCTAssertNil(ReminderParse.parse("bad | 2026-06-31", now: 0), "June has 30 days")
        XCTAssertNil(ReminderParse.parse("bad | 2026-02-29", now: 0), "2026 isn't a leap year")
        XCTAssertNil(ReminderParse.parse("bad | 2026-13-01", now: 0), "month > 12")
        XCTAssertNil(ReminderParse.parse("bad | 2026-08-01 24:00", now: 0), "hour > 23")
        XCTAssertNil(ReminderParse.parse("bad | 2026-08-01 12:60", now: 0), "minute > 59")
    }
}